data () {
	return {
	    active: 0,
		isFixed: false
	}
},
methods: {
	handleScroll () {
      let scrollY = window.pageYOffset ||
          document.documentElement.scrollTop ||
          document.body.scrollTop
      let scrollObj = document.querySelector('#yj_bot').offsetTop
      if (scrollY >= scrollObj) {
        this.isFixed = true
      } else {
        this.isFixed = false
      }
    }
},
mounted () {
	window.addEventListener('scroll', this.handleScroll)
}
